An apparatus for a three-stage cooling and scrubbing system for the treatment of hot crude gases and liquid slag downstream of an entrained flow gasification. crude gas and slag are firstly cooled and prescrubbed in a first stage by injection of water from ring and/or wall nozzles into a free quench space. crude gas and slag are then fed together with excess water into a waterbath as a second stage before intensive spraying is once again carried out as a third cooling and scrubbing stage in an annular space.
|
1. An apparatus for treating hot crude gases and liquid slag having temperatures of 1200-1800° C. and pressures of up to 10 MPa in an entrained flow gasification of fuel dust, the apparatus comprising a gasification reactor, a quencher, a crude gas and slug outlet, a crude gas outlet, a funnel, first nozzles, and second nozzles,
wherein
the quencher is arranged downstream of the gasification reactor, and the quencher and the gasification reactor are surrounded by a pressure wall;
the crude gas and slag outlet connects the gasification reactor to the quencher;
the quencher has an inner wall spaced inward of the pressure wall;
a waterbath is located in a lower part of the quencher;
a free space quench is located in the quencher in flow succession after the crude gas and slag outlet, the free space quench having the first nozzles located and configured for injecting cooling and scrubbing water into the free space quench;
the funnel is located in the quencher inside the inner wall and downstream of the free-space quench;
the funnel has an upper end in contact with the inner wall of the quencher and has an open lower end dipping into the waterbath;
an annular space is formed between the funnel, a surface of the waterbath, and the inner wall of the quencher;
the crude gas outlet is connected to the annular space for the flow of crude gas that has passed downward through the funnel, downward through the waterbath, upward through the waterbath, and upward through the annular space, the flow of crude gas flowing through the crude gas outlet outside of the pressure wall;
the second nozzles are configured and located above the surface of the waterbath for injecting cooling and scrubbing water, the second nozzles being arranged inside the annular space; and
the inner wall bounds the free space quench in the radial direction with respect to the central longitudinal axis of the quencher.
2. The apparatus as claimed in
3. The apparatus as claimed in
4. The apparatus as claimed in
5. The apparatus as claimed in
6. The apparatus as claimed in
7. The apparatus as claimed in
8. The apparatus as claimed in
|
The present application claims priority of German Patent Application No. 102014201890.0, filed Feb. 3, 2014, the contents of which are incorporated by reference herein.
The invention relates to an apparatus of a combined quenching and scrubbing system for the cooling and purification of crude gases from an entrained flow gasification plant in which fuel dusts are reacted with oxygen and moderated by such as steam or else carbon dioxide at temperatures of 1200-1900° C. and pressures of up to 10 MPa to give a CO- and H2-rich crude gas.
For the purposes of the present invention, fuel dusts are finely milled coals having different degrees of carbonization, dusts composed of biomasses, products of thermal pretreatment, e.g. coke, dried products obtained by “torrefaction” and also calorific fractions from domestic and industrial residues and wastes. The fuel dusts can be fed as a gas-solid or liquid-solid suspension to the gasification. The gasification reactors can be provided with a cooling shield or with a refractory lining, as disclosed in the patents DE 4446803 and EP 0677567. In various systems which have been introduced into industry, crude gas and the molten slag can be discharged separately or together from the reaction space of the gasification apparatus, as described in DE 19718131.
Owing to the fuel particles which have been milled to dust fineness and short reaction times in the gasification space, entrained flow gasification results in an increased proportion of dust in the crude gas. This fly dust consists, depending on the reactivity of the fuel, of soot, and reacted fuel particles and also fine slag and ash particles. The size varies from coarse particles having diameters of greater than 0.5 mm to fine particles having a diameter of up to 0.1 The ease with which the particles can be separated from the crude gas is dependent on this diameter but also on the composition of the particles. A distinction can basically be made between soot and ash or slag particles, with soot particles generally being smaller and more difficult to separate from the crude gas. Slag particles have a higher density and are thus easier to separate off, but have a greater hardness and erosive effect. This leads to increased wear in the lines conveying the crude gas and can result in safety-relevant leaks and decreases in the life of these plant components. Various scrubbing systems are used for removing the dusts resulting from the fuels.
Prior art is summarized in the patent document DE 10 2005 041 930 and in “Die Veredelung and Umwandlung von Kohle” DGMK, Hamburg, December 2008, Schingnitz, chapter “GSP-Verfahren”. According to this, the crude gasification gas together with the slag formed from the fuel ash leaves the gasification space at temperatures of 1200-1900° C. and is cooled in a downstream quenching space by spraying in excess water and is freed of the slag and to a small extent of entrained dust, with the quenching space being able to be configured as a free-space quencher or be equipped with a central tube conveying crude gas. A free-space quenching system is disclosed, for example, in DE 10 2007 042543, in which the crude gas leaving the gasification space is sprayed with water and taken off in the lower part under a roof construction. DE 10 2006 031816 discloses a free quenching space completely without internals, with quenching water being injected at one or more levels in such an amount that the crude gas is cooled and saturated with water vapor and the excess quenching water is taken off either alone or together with precipitated slag in the lower part. Variants having a central tube are disclosed in the patent DE 199 52 754, in which the central tube is configured in the form of a Venturi tube, DD 145860, in which the crude gas is subjected to an additional scrub in the form of an airlift pump, and DD 265051, in which elements for distributing the exiting crude gas at the end of the central tube are supposed to ensure uniform outflow. CN 101003754-B describes an immersion quenching apparatus having a central tube in which the hot crude gas from the gasification reactor is conveyed together with the likewise hot slag downward into water beneath the surface thereof and flows upward as gas-water suspension in the annular gap of the guide tube configured as a double tube. Gas-water separation occurs at the upper end of the guide tube. The gas-water suspension flowing upward in the annular gap is said to protect the inner central tube against overheating.
The solution to the problem proposed in the patent DE 10 2007 042 543 has the disadvantage that the free space through pipes having a relatively large diameter for discharging the crude gas and the roof construction provides deposition surfaces for entrained slags and dusts, which experience has shown leads to blockages. DE 10 2006 031816 requires uniform outflow of the hot crude gas from the gasification space because otherwise there could be a risk of thermal overloading of the pressure-rated vessel walls. The installation of a Venturi tube as described in DE 199 52 754 can lead to undesirable pressure fluctuations in the gasification space which are difficult to equalize by regulation technology because of their brief duration. Internals in the quenching and scrubbing space, as described in the patents DD 265051 and DD 145860, can lead to cement-like products due to the pozzolanic properties of, in particular, the fine dust components in the case of particular types of coal and ash and these likewise lead to blockages and an increase in the pressure drop. This risk is likewise present in the case of the problem solution proposed in CN 101003754-B. The gap between the inner and outer tubes of the central tube can become blocked, and the hot crude gas flowing downward in the uncooled inner tube can lead to thermal destruction of the inner tube and additionally endangers the pressure wall of the quenching space by overheating.
It is an object of the invention to provide an apparatus for cooling the hot gasification gas and the entrained liquid slag, in which, firstly, cooling of the hot crude gas down to the temperature of water vapor saturation determined by the process pressure and, secondly, simultaneous deposition of slag and dust and also a high proportion of hydrogen in the crude gas are achieved.
According to the invention, a plurality of first cooling and scrubbing stages connected in series are combined with one another. The hot crude gasification gas leaves the gasification reactor together with the liquid slag formed from the fuel ash via a specific outflow device and goes into a free-space quencher as first stage. Cooling down to the process pressure-dependent saturation temperature and first coarse separation of dust are achieved by injection of cooling and scrubbing water into the hot gas stream via a nozzle ring 13 directly on the outflow device. The amount of water injected is such that the subsequent components are sufficiently wetted. The free-space quench is terminated at the bottom by a funnel-shaped insert 9 which guides the precooled crude gas and the slag via a tubular extension into a waterbath 7 as a second treatment stage. While relatively coarse slag particles separate off in a downward direction, fine dust is bound in the waterbath through which the crude gas flows in the manner of a bubble column. The crude gas leaving the bubble column is, before leaving the cooling and scrubbing apparatus, once again treated with scrubbing water via a nozzle ring 5 as a third stage in order to retain as much fine dust as possible. As a result of the combination of the cooling and scrubbings connected in series and the conversion reaction between carbon monoxide and water vapor proceeding during cooling of the crude gas by means of water, a high proportion of hydrogen in the crude gas is achieved. The cooled and scrubbed water vapor-saturated crude gas is subsequently passed to further external treatment stages.
To protect the pressure wall 3 against overheating, particularly in the region of the free-space quench, an inner water wall 10 can be provided. Furthermore, it is possible to convey the crude gas into the bubble column through a guide ring 17.
The invention is illustrated below by means of an example with the aid of two figures. The figures show:
In the Figures, identical reference numerals denote identical elements.
In a gasification reactor 1 as per
In a particular embodiment in
The apparatus of the invention also makes it possible to perform a process in which
In an apparatus in which an inner wall 4 is arranged in the quencher, the annular gap 10 between the pressure wall 3 and the inner wall 4 is, in an inventive embodiment of the invention, continuously flushed with water.
In an apparatus in which an inner wall 4 is arranged in the quencher and in which the annular gap 10 between the pressure wall 3 and the inner wall 4 is continuously flushed with water, the water leaving the annular gap 4 as a water wall runs down as a water film on the inside of the inner wall 4.
In an apparatus in which an inner ring 17 is arranged in the free space, the bubble column in the waterbath 7 is, in an inventive embodiment of the process, kept away from the inner wall 4 by the inner ring 17, with the crude gas experiencing another change in direction at the upper end of the inner ring 17.
Hannemann, Frank, Schingnitz, Manfred, Toth, Heidrun
Patent | Priority | Assignee | Title |
Patent | Priority | Assignee | Title |
2931715, | |||
4326856, | Mar 30 1979 | Texaco Development Corporation | Production of cleaned and cooled synthesis gas |
4328006, | May 30 1979 | Texaco Development Corporation | Apparatus for the production of cleaned and cooled synthesis gas |
4377132, | Feb 12 1981 | Texaco Development Corp. | Synthesis gas cooler and waste heat boiler |
4377394, | May 30 1979 | Texaco Development Corporation | Apparatus for the production of cleaned and cooled synthesis gas |
4466808, | Apr 12 1982 | Texaco Development Corporation | Method of cooling product gases of incomplete combustion containing ash and char which pass through a viscous, sticky phase |
4474584, | Jun 02 1983 | Texaco Development Corporation | Method of cooling and deashing |
4494963, | Jun 23 1983 | Texaco Development Corporation | Synthesis gas generation apparatus |
4520760, | Apr 23 1984 | Combustion Engineering, Inc. | Heat exchanger outlet arrangement |
4605423, | Apr 12 1982 | Texaco Development Corporation | Apparatus for generating and cooling synthesis gas |
4768470, | Jul 02 1986 | ABB MANAGEMENT LTD | Gas cooler for synthesis gas |
4778483, | Jun 01 1987 | Texaco Inc. | Gasification reactor with internal gas baffling and liquid collector |
4852997, | Oct 05 1987 | Shell Oil Company | Slag water bath process |
5324336, | Sep 19 1991 | Texaco Inc. | Partial oxidation of low rank coal |
5968212, | Oct 19 1996 | Siemens Aktiengesellschaft | Apparatus for gasification of combustion and waste materials containing carbon and ash |
5976203, | Apr 08 1997 | Metallgesellschaft Aktiengellschaft | Synthesis gas generator with combustion and quench chambers |
7090707, | Nov 02 1999 | Combustion chamber design for a quench gasifier | |
8187349, | Mar 15 2007 | Air Products and Chemicals, Inc | Gasification reactor vessel |
8240259, | Jul 07 2006 | SIEMENS ENERGY GLOBAL GMBH & CO KG | Method and apparatus for cooling hot gases and fluidized slag in entrained flow gasification |
8770555, | Sep 07 2007 | CCG ENERGY TECHNOLOGY COMPANY LTD | Method and device for treating charged hot gas |
8986403, | Jun 30 2009 | Air Products and Chemicals, Inc | Gasification system flow damping |
20070044381, | |||
20080222955, | |||
20090126259, | |||
20100139581, | |||
20100143216, | |||
CN101003754, | |||
CN101675146, | |||
CN101935554, | |||
CN102239235, | |||
CN102382685, | |||
DE102005047930, | |||
DE102006031816, | |||
DE102007042543, | |||
DE145860, | |||
DE19718131, | |||
DE19952754, | |||
DE224045, | |||
DE265051, | |||
DE4446803, | |||
EP677567, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Feb 03 2015 | Siemens Aktiengesellschaft | (assignment on the face of the patent) | / | |||
Mar 27 2015 | TOTH, HEIDRUN | SIEMENS FUEL GASIFICATION TECHNOLOGY GMBH & CO KG | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 035563 | /0711 | |
Mar 27 2015 | HANNEMANN, FRANK | Siemens Aktiengesellschaft | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 035564 | /0164 | |
Apr 01 2015 | SCHINGNITZ, MANFRED | SIEMENS FUEL GASIFICATION TECHNOLOGY GMBH & CO KG | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 035563 | /0711 | |
Apr 02 2015 | SIEMENS FUEL GASIFICATION TECHNOLOGY GMBH & CO KG | Siemens Aktiengesellschaft | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 035563 | /0855 | |
Feb 28 2021 | Siemens Aktiengesellschaft | SIEMENS ENERGY GLOBAL GMBH & CO KG | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 056500 | /0414 |
Date | Maintenance Fee Events |
Sep 16 2020 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Date | Maintenance Schedule |
Jul 04 2020 | 4 years fee payment window open |
Jan 04 2021 | 6 months grace period start (w surcharge) |
Jul 04 2021 | patent expiry (for year 4) |
Jul 04 2023 | 2 years to revive unintentionally abandoned end. (for year 4) |
Jul 04 2024 | 8 years fee payment window open |
Jan 04 2025 | 6 months grace period start (w surcharge) |
Jul 04 2025 | patent expiry (for year 8) |
Jul 04 2027 | 2 years to revive unintentionally abandoned end. (for year 8) |
Jul 04 2028 | 12 years fee payment window open |
Jan 04 2029 | 6 months grace period start (w surcharge) |
Jul 04 2029 | patent expiry (for year 12) |
Jul 04 2031 | 2 years to revive unintentionally abandoned end. (for year 12) |